I've always used the shoutcast server from winamp. It's not imbeded into the website, but you can make the link that will open people's winamp and start playing it. Otherwise, I'd suggest using vlc player's technology.
If you don't want to go with internet radio, I know there's info on embeded media in "html" 5th edition quickstart guide.
If you have cable modem (4mb) then why not just use your own computer and broadcast with an encoder? Use Windows Media Encoder (sorry have more experience with it) and just start it up, choose a 40kb stream for audio and off you go. You post the url on your website and they click into the stream. 4mb could give you almost 100 listners without the need for some service. Hosting encoded files is even easier and only needs a .htaccess file to stream from most servers.